1. M. G. Krein and G. K. Langer, ?On certain mathematical principles of the linear theory of damped oscillations of continua,? in: Proc. Int. Symp. on the Application of the Theory of Functions of a Complex Variable in Continuum Mechanics, Tbilisi, 1963, Vo. II [in Russian], Nauka, Moscow (1965), pp. 283?322.
2. A. G. Kostyuchenko and M. B. Orazov, ?On the completeness of the root vectors of certain self-adjoint quadratic pencils,? Funkts. Anal. Prilozhen.,11, No. 4, 85?87 (1977).
3. M. B. Orazov, ?On certain properties of analytic operator-functions, of two arguments,? Usp. Mat. Nauk,33, No. 4, 221?222 (1978).
4. M. B. Orazov, ?On the completeness of the eigen- and associated vectors of a self-adjoint quadratic pencil,? Funkts. Anal. Prilozhen.,10, No. 2, 82?83 (1976).
5. V. D. Kupradze, T. G. Gegelia, M. O. Basheileishvili, and T. V. Burchuladze, Three-Dimensional Problems of the Mathematical Theory of Elasticity and Thermoelasticity [in Russian], Nauka, Moscow (1976).